Briquet composition and proces of making briquets.



E. A. PATERSON.

BRIQUET COMPOSITION AND PROCESS OF MAKING BRIQUETS.

APPLIGATION FILED DEO,26.1913.

Patented Sept. 29, 1914.

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EDWARD ALFRED PATERSON, or roar ARTHUR, ONTARIO, CANADA.

BRIQUET COMPOSITION AND PROCESS OF MAKING BRIQUETS.

Specification of Letters lfatent. Patented S pt 29 1914 Application filed December 26, 1913. Serial No. 808,866.

To all whom. it may concern Be it known that I, EDWARD A. PATERSON, a subject of the ,King of Great Britain, residing at Port Arthur, Province of Ontario, and Dominion of Canada, have invented certain new and useful Improvements in Briquet Compositions and Processes of Making Briquets, of which the following is a specification.

Myinve'ntion relates to a method of and a composition for reassembling in any desired form suitable for'the blast furnace, fine ore concentrates and dust containing silica, fine ore, iron ore flue dust, and the iron residues obtained from sulfuric acid 'ovorks wherein iron pyrites are roasted: Briqueting fine iron ore is done at the present time by various methods, but these methods require expensive machinery, and the cost of operation is heavy. I have found it advisable .to treat the ore in the following way, which is economical and puts the material in good condition for the furnace.

Briquets, as heretofore made, have been usually hard and smooth, and frequently do not offer sufiicient points for attack by the heat, but in some cases this form of the material is preferred, as somefurnace men, be ing accustomed to some particular shape desire to have the material compressed into briquets of that shape. Mine are prefer ably somewhat irregularin shape, or lumpy. The accompanying drawing shows ap apparatus by means of which my process may be effectively carried out. i

Figure 1 shows a general view of the apparatus partly in side elevation and partly in section and w th some of the'parts broken away. Fig. 2is a detail view inperspective of the mold faced roll employed.

1 indicates an ordinary mixing machine, such as a concrete mixer, into the hopper 2 of which the fine ore, water and silicate are put. These, when mixed, are discharged upon a belt 3, which may be an endless steel band or of some other material heavy enough to carry the ore and sufficiently resistant to the heat. At 4, I have shown a corrugated or mold-faced roll. Opposed to this is a roll 5.. Between these the belt laden with the wet :ore mass is carried and the-mass is brokenror out up or molded by the moldshaped roll into more or less uniformly sized rough masses or lumps, without much pressure.

Just before the mass is discharged upon the belt, at 6, I distribute upon the belt a layer of ore dust discharged down thec hute 7 from a bin or hopper 8. This ore dust prevents the lumps or masses of ore from sticking to the belt, and itself adhering to the lumps, gives them a rough surface, yielding readily to the smelting action. Below the upper course of this belt I have indicated 'a heater 9, i. e. a gas pipe with a number of burners, though, of course, other heating means may be used. This belt should be long enough and should move at such speed that the briquets or lumps are dry enough to be hard when they are finally discharged at 10, passing from the belt to the discharging point down chute 11. The upper part of this chute is perforated or' reticulated at 11, so that any unattached ore dust will fall off and be discharged into a box 12, whence it may be lifted by conveyer 13 to hopper 8. In said hopper 8 I provide a stirrer 14,. A shaking table 15 maybe used, discharging through tube or funnel 16 at or near the exit opening of the hopper.

It will be noted that by drying the lumps or briquets before they are removed from the belt, I avoid the danger of their breaking or crumbling. I

The fine ore is mixed with the calculated amount of flux, and to this is added ten to fifteen per cent. of water, if the material is dry, and from five to ten per cent. of silicate of soda solution of 50 Twaddell. After the materials have been well mixed the charge is fed onto the traveling belt which is heated to from 120 to 150 degrees 0., thelength of the belt being so adjusted that the material isfrom fifteen to twentyminutes exposed to the heat. The thickness of the material must, of course, be adjusted to give' a hard and compact product after it leaves the belt. The silicate of soda dries and the particles cohere together.

enough to take care of all the silica in the.

ore. This base, ordinarily would be lime preferably in the form of limestone which is the cheapest. Limeitself is not a very good agglomerant. I find it useful to use an alkaline silicate as an agglomerant or hinder. The silicate which I prefer to use is a hydro-us silicate of sodium which has,

as compared with other alkali silicates,;

usually available, a larger proportion of sihcic acid. The formation of this is typilied by the formula Na Oyn sio (H O) ac.

mosphere which goes to the sodium base ofthe silicate forming sodium carbonate and freeing the hydro-silicic acid, which thus becomes the effective binder of the briquet. The calcium carbonate remains unchanged at the end of the reaction and I attribute to this carbonate a catalytic efiect during the progress of the change. That is, I am of the opinion that the calcium carbonate passes one molecule of CO over to the soda, and

takes another molecule of CO from the air, and that it will keep this up until all the soda changes to carbonate, or until the mass becomes too dry for the reaction to occur. Without the catalytic agent the action ofthe CO upon the sodium component of the silicate is much slower.

Briquets thus made can be smelted in an ordinary manner, and during the smelting the soda will mainly be volatilized. Enough limestone must be added to take care of the additional silicic acid, which is not changed, used in the binder.

If it is desired to lump the material without the flux, I treat it mechanically in the presence of CO in the same way indicated above, but I only use from four to six per cent. of the silicate solution and the same quantity of water. I simply add the water so as to get the materials well mixed together, and as thewater has to be evaporated later, I merely use enough to make the mixture into a somewhat stiff plastic condition. If I use five per cent. of the silicate solution of the above indicated strength, the amount of real silicate is about one per cent, and if I use the hydrous silicate I make allowance for the combined water; and on the other hand, I add more water if the hydrous silicate be mixed with the other materials before the water was added in the mixer, that is, instead of ten to fifteenper 'cent. water I use fifteen to twenty-five per cent.

The following proportions are suggested. Much depends upon the character of the ore: fine iron ore 100 grams, water 15 c.c., silicate of soda 4: c. c. of T. With the flux added these proportions may be used: fine iron ore 77 grams, water 15 c. c., limestone 33 grams, silicate 10 c. c.

In the smelting operation the small amount of alkali undoubtedly aids the lime somewhat in fluxing the silica, but probably before the smelting operation is complete, asindicated above, most of this alkali disappears through volatilization.

I claim as my invention:

1. The process of briqueting a silicious ore, which consists in. mixing with ahydrous alkali silicate an alkali earth carbonate, and agglomerating said ore with said mixture.

2. The process of briqueting a silicious ore, which consists in mixing with an alkali silicate, a hydrous alkali earth carbonate, and agglomerating said ore with said mixture, the quantity of alkali earth carbonate being proportioned to the total quantity of silicic acid in the agglomerated briquet.

3. The process of briqueting silicious iron ore, which consists in mixing with hydrous sodium silicate pulverized limestone and br-iqueting said ore with said mixture.

4. The process of briqueting silicious ore, which consists in mixing with hydrous sodium silicate an alkali earth carbonate, agglomerating said ore with said mixture, the quantity'of said carbonate being proportioned to the total quantity of the silicic acid in the finished briquets, and exposing them to the hardening effect of carbon dioxid.

5. A process for briqueting or lumping ore dust, which consists in mixing said ore dust with a hydrous alkali silicate, in solution, and water, discharging upon a suitable surface a layer of powdered ore, dischar ing upon said layer the mixed ore and si icate', molding or lumping said mixture upon said surface, drying the lumps so formed upon the same surface, discharging the said lumps from said surface, and at the same time separating from said lumps any unattached powdered ore.

6. A process for briqueting or lumping fine ore, which consists in mixing to a stiff plastic condition said ore with hydrousalkali silicate, in solution, water and pulverized limestone, discharging upon a suitable moving surface a layer of powdered ore, discharging-upon said layer the mixture of ore, water, silicate and limestone, molding or lumping it upon said surface, causing the lumps so formed to pass undisturbed upon said surface through a drying zone until the lumps become hard, and

then passing the lumps off said surface and at'the same time separating from said lumps any unattached ore.

7. A process for briqueting or lumping o-re dust, which consists in mixing said ore dust with hydrous alkali silicate, in solution, and water, discharging upon a suitthe said lumps from said surface, and at thesame time separating from said lumps any unattached powdered ore, and finally exposing said lumps to the hardening efiect of carbon dioxid.

8. A composition for briqueting pulverized ore, which consists of a mixture of a.

,hydrous'alkali silicate and an alkali earth carbonate. 1

'9. A composition for briquetlng pulverized 'ore, which consists of h drous sodium 20 silicate and limestone pulverized, the quantity of limestone being proportioned to the total quantity of silica in the silicate and invthe ore.

In testimony whereof, I have hereunto 25 subscribed mfi name.

EDWA

Witnesses:

Lnwrs T. PAYNE, ELsm Somurrr.

n ALFRED PATERSON. 

